# AcyMailing – An Ultimate Newsletter Plugin and Marketing Automation Solution for WordPress <= 11.1.0 - Unauthenticated Stored Cross-Site Scripting via Subscriber Name and Custom Field Values

- **ID:** WPSEC-2026-0470
- **Plugin:** AcyMailing – An Ultimate Newsletter Plugin and Marketing Automation Solution for WordPress (`acymailing`), https://wordpress.org/plugins/acymailing/
- **Affected versions:** all versions before 11.1.1
- **Fixed in:** 11.1.1 (Update to 11.1.1 or later.)
- **Severity:** Medium 6.1 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N)
- **Weakness:** CWE-79
- **Usage among sites WPSec scans:** plugin Medium, affected versions Low (as of 2026-10-06)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/acymailing
- **Fix released:** 2026-10-05
- **Published:** 2026-10-06
- **URL:** https://wpsec.com/vuln/WPSEC-2026-0470/

## Description

The AcyMailing plugin for WordPress is vulnerable to Stored Cross-Site Scripting via subscriber names and custom field values in all versions up to, and including, 11.1.0. This is due to insufficient input sanitization and output escaping when subscriber data is inserted into emails shown on the plugin's 'view online' archive page. Custom field values were inserted into the email without escaping, and the page re-decoded HTML entities in the email body before injecting it as HTML. This makes it possible for unauthenticated attackers to submit malicious values through the public subscription form and inject arbitrary web scripts. The scripts execute when a user, such as an administrator opening an email from the subscriber's history, views an email rendered with that subscriber's data.

## References

- https://wpsec.com/vuln/WPSEC-2026-0470/
- https://plugins.svn.wordpress.org/acymailing/tags/11.1.1/
- https://wordpress.org/plugins/acymailing/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-0470/

License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Free to use, share and adapt, also commercially, if you credit WPSec and link to this advisory.